This study is to determine the extent of acceptance by children of caries preventive procedures as a result of method of persuasion. It will be conducted as two separate experiments. One experiment will require low effort from subjects while the second will require high effort. The low effort experiment will require children to come to their own school three times in 11 months for an application of an acidulated fluoride gel. The high effort experiment will require children to use an acidulated fluoride mouthrinse at home 5 days per week for 6 months. Each experiment will use a sample of between 300 and 325 children. Half the children in each experiment will be from 2 classes of 3 urban junior high schools; the other half will be from 2 classes of 3 suburban junior high schools. In each experiment two methods will be used to increase acceptance of caries preventive procedures: (1) a "group discussion-attitude change" procedure and (2) a "contingency management-behavior modification" procedure. For comparison, a control group which does not receive unusual motivational impetus will carry out dental procedures in each experiment. Each method will be used in one urban and one suburban school. Measures will be made of: (1) amount of acceptance of required procedures, (2) social-psychological characteristics of children who volunteer to participate in the dental studies and those who do not, (3) social-psychological characteristics of children who accept procedures and those who do not, and (4) characteristics of parents whose children accept procedures and those who do not. These measures will be made within each experiment separately and then combined for the two studies. Data from this study will be valuable for making decisions about the form of new caries preventive agents and the means they should be provided for mass caries prevention programs. In addition, data will be provided about efficient means for persuading children to use anti-caries agents on a mass basis.